# Why are indicators used only in the form of dilute solutions?

Why are indicators used only in the form of dilute solutions? I get that indicators are a form of weak acids themselves, and the extent of their dissociation varies with the pH of the solution they are in.

• indicators 1) are very costly 2) affect pH of the solution itself. – permeakra Nov 7 '17 at 12:21
• And visual recognition of their virage interval! – Alchimista Nov 7 '17 at 12:34